KOWA FM-600

{0} **FDA U.S. FOOD & DRUG** ADMINISTRATION September 11, 2026 Kowa Company, Ltd. Chofu Factory % Nana Nagashita Regulatory consultant Ken Block Consulting Co., Ltd. 1-9-9 Hosokawatsukiji Bldg., Tsukiji Cyuo-Ku Tokyo, 104-0045 Japan Re: K261255 Trade/Device Name: Kowa Fm-600 Regulation Number: 21 CFR 886.1570 Regulation Name: Ophthalmoscope Regulatory Class: Class II Product Code: MYC Dated: August 5, 2026 Received: August 6, 2026 Dear Nana Nagashita: We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading. If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register. U.S. Food & Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993 www.fda.gov {1} K261255 - Nana Nagashita Page 2 Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download). Your device is also subject to, among other requirements, the Quality Management System Regulation (QMSR) (21 CFR Part 820), which includes, but is not limited to, ISO 13485 clause 7.3 (Design controls), ISO 13485 clause 8.3 (Nonconforming product), ISO 13485 clause 8.5.2 (Corrective action), and ISO 13485 clause 8.5.3 (Preventative action). Please note that regardless of whether a change requires premarket review, the QMSR requires device manufacturers to review and approve changes to device design and production (ISO 13485 clause 7.3 and ISO 13485 clause 7.5) and document changes and approvals in the Medical Device File (ISO 13485 clause 4.2.3). Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the Quality Management System Regulation (QMSR) (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050. All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems. For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). {2} K261255 - Nana Nagashita Page 3 Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100). Sincerely, # BRADLEY S. CUNNINGHAM -S CAPT Bradley Cunningham, MSE, RAC Acting Assistant Director DHT1A: Division of Ophthalmic Devices OHT1: Office of Ophthalmic, Anesthesia, Respiratory, ENT, and Dental Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health Enclosure {3} | Indications for Use | | | | --- | --- | --- | | Please type in the marketing application/submission number, if it is known. This textbox will be left blank for original applications/submissions. | K261255 | ? | | Please provide the device trade name(s). | | ? | | KOWA FM-600 | | | | Please provide your Indications for Use below. | | ? | | KOWA FM-600 is an instrument to measure the protein level contained in aqueous humor of the anterior chamber of human eye. | | | | Please select the types of uses (select one or both, as applicable). | ☑ Prescription Use (21 CFR 801 Subpart D) ☐ Over-The-Counter Use (21 CFR 801 Subpart C) | ? | {4} K261255  # Kowa Company, Ltd. Chofu Factory 3-1 Chofugaoka 3-chome, Chofu City Phone:81-42(440)7612 Tokyo 182-0021, Japan FAX :81-42(440)7616 # 510(k) Summary Date of preparation: August 31st, 2026 # Contact Details | Applicant Name | Kowa Company, Ltd. Chofu Factory | | --- | --- | | Applicant Address | 3-1 Chofugaoka 3-chome Chofu Tokyo 182-0021 Japan | | Applicant Contact Telephone | 81+42-440-7630 | | Applicant Contact | Mr. Kazunori Matsumura | | Applicant Contact Email | kamatamr@kowa.co.jp | | Correspondent Name | Ken Block Consulting Co., Ltd. | | Correspondent Address | 1-9-9 HosokawaTsukiji Building, Tsukiji Cyuo-ku Tokyo 104-0045 Japan | | Correspondent Contact Telephone | +81-3-6260-6688 | | Correspondent Contact | Ms. Nana Nagashita | | Correspondent Contact Email | nagashita@kenblockconsulting.com | # Device Name | Device Trade Name | KOWA FM-600 (LSS50D2) | | --- | --- | | Common Name | Ophthalmoscope | | Classification Name | Ophthalmoscope, Laser, Scanning | | Regulation Number | 886.1570 | | Product Code(s) | MYC | | Class | II | # Legally Marketed Predicate Devices | Predicate # | K091039 | | --- | --- | | Predicate Trade Name (Primary Predicate is listed first) | KOWA FM-600 | | Product Code | MYC | Page 1 {5} K261255 ## Device Description Summary The KOWA FM-600, hereinafter referred to as FM-600, is a noninvasive flare photometry medical device that can quantitatively assess anterior protein level in the anterior chamber of the human eye. FM-600 is a prescription device, intended to be used by an ophthalmologist or ophthalmic technician. FM-600 is an electro-optical software-controlled medical device consisting of three units: Measurement unit, Operating unit and Power supply unit with two operating modes (Automatic and Manual). The measurement unit contains the FM-600 optical system, which includes the laser, photoreceiver and CCD camera for observation. The light sources of FM-600 are a laser diode for flare measurement and an LED light for illumination to observe the measurement area. The operating unit contains the observation monitor, analyzer of detected photon intensity, printer for output, and migratory mechanism of the units. The power supply unit contains the AC/DC electrical supply and control mechanism. The optical system is composed of a laser beam emitter and a photoreceiver positioned orthogonal to the axis of the beam. The scanning laser beam is focused at the target point in the anterior chamber. Scattered light from the anterior chamber is detected by the photoreceiver through a photoreceiver mask. The photoreceiver mask plays an important role to create a measurement window in the anterior chamber, of which position is optically matched with the target position. Scattered light passing through the mask reaches the photoreceiver, and then the light intensity signal is converted to an electrical signal with the photoreceiver. Then, the collected signal is analyzed in the analyzer unit to determine a flare value. The results are shown on the LCD monitor. ## Intended Use/Indications for Use KOWA FM-600 is an instrument to measure the protein level contained in aqueous humor of the anterior chamber of human eye. ## Technological Comparison The subject device has the same fundamental measurement principle and operating principle as the predicate device (K091039). The main technological differences from the predicate device are as follows (see Table 1): - Laser source wavelength: Changed from 635 nm to 638 nm. Slightly longer wavelength. - Laser scanning mechanism: Changed from Galvanometer to MEMS mirror. - Laser output: ≤ 50 μW for the predicate device and 35 ± 15 μW for the subject device. A plus minus tolerance has been introduced for the subject device. Page 2 {6} K261255 Maximum intensity is same. - Input terminal: Changed from PS/2 terminal to USB terminal. - Chin rest and forehead rest: The color changed from yellow to green. - Alignment mode: Front view alignment mode has been added to the subject device. Table1 Comparison of the subject device against the predicate device | | Subject Device | Predicate Device | Comparison | | --- | --- | --- | --- | | Trade Name | KOWA FM-600 | KOWA FM-600 | | | 510(k) Number | K261255 | K091039 | | | 510(k) Submitter | KOWA Company, Ltd. | KOWA Company, Ltd. | Same. | | Device Class | Class II | Class II | Same. | | Product Code(s) | MYC | MYC | Same. | | Regulation | 886.1570 | 886.1570 | Same. | | Classification Panel | Ophthalmic | Ophthalmic | Same. | | Intended Use | KOWA FM-600 is an instrument to measure the protein level contained in aqueous humor of the anterior chamber of human eye. | KOWA FM-600 is an instrument to measure the protein level contained in aqueous humor of the anterior chamber of human eye. | Same. | | OTC/ Rx | Rx | Rx | Same. | | Flare Measurement Functions and Principal parts | | | | | Wavelength of Laser source | 638 nm | 635nm | Different. Slightly longer wavelength. | | Laser scanning width | 0.6 mm | 0.6 mm | Same. | | Beam west diameter | 20μm | 20μm | Same. | | Laser light intensity at the subject eye | 35±15 μW | Less than 0.05mW | Different. A plus minus tolerance has been introduced for the subject device. Maximum intensity is | Page 3 {7} K261255 | | Subject Device | Predicate Device | Comparison | | --- | --- | --- | --- | | Trade Name | KOWA FM-600 | KOWA FM-600 | | | | | | same. | | Photo detector | Photo multiplier tube | Photo multiplier tube | Same. | | Measurement range | 1 to 500 Photon count/ms | 1 to 500 Photon count/ms | Same. | | Measurement area | 0.3 (H) x 0.5 (W)mm | 0.3 (H) x 0.5 (W)mm | Same. | | Measurement time | 0.5 second | 0.5 second | Same. | | Measurement distance | 81 mm (Patient's eye to objective lens) | 81 mm (Patient's eye to objective lens) | Same. | | Illumination light source | Infrared LED | Infrared LED | Same. | | Observation method | Electrical image by CCD camera | Electrical image by CCD camera | Same. | | Fixation light source | Visible LED | Visible LED | Same. | | Laser scanning element | MEMS mirror | Galvanometer | Different. Changed from Galvanometer to MEMS mirror | | Alignment mode | Front view alignment Side view alignment | Side view alignment | Different. Front view alignment mode has been added to the subject device. | | Hardware | | | | | Dimension/Weight | 274(W) x 457 (D) x 458 (H) mm /18 kg | 274(W) x 457 (D) x 458 (H) mm /18 kg | Same. | | Input terminal | USB terminal | PS/2 terminal | Different. Changed from PS/2 terminal to USB terminal. | | LCD monitor | 5.6 inch TFT color LCD | 5.6 inch TFT color LCD | Same. | | Accessories | Power cable, Fuses, Dust cover, Chin-rest paper, Chin-rest's pins, and Printer papers. | Power cable, Fuses, Dust cover, Chin-rest paper, Chin-rest's pins, and Printer papers. | Same. | | Options | Numerical keypad, | Numerical keypad, | Same. | Page 4 {8} K261255 | | Subject Device | Predicate Device | Comparison | | --- | --- | --- | --- | | Trade Name | KOWA FM-600 | KOWA FM-600 | | | | Barcode reader, and Light shade. | Barcode reader, and Light shade. | | | Biocompatibility | | | | | Chin rest Forehead rest | - Intact skin - Limited contact duration (≤24 h) - Green color | - Intact skin - Limited contact duration (≤24 h) - Yellow color | The color changed from yellow to green | The following tests and evaluations were conducted to compare the safety and effectiveness of the subject device and the predicate device [K091039]. ### Clinical Test N/A ### Non-Clinical Tests Summary Two performance equivalence testing were conducted, as described below. - **Equivalence Verification of Flare Meter KOWA FM-600, Model LSS50D2 with Predicate Device LSS50** Using the subject device and the predicate device, the correlation of flare values by Deming regression, the differences in flare values by Bland-Altman analysis, the repeatability of flare values, and the reproducibility of flare values were evaluated. The results confirmed that the subject device is substantially equivalent to the predicate device. - **Equivalence Verification of Front View Alignment with Side View Alignment Using KOWA FM-600, Model LSS50D2** Using the subject device, the correlation of flare values by Deming regression, the differences in flare values by Bland-Altman analysis, and the repeatability of flare values were evaluated between the new alignment procedure (front view alignment) and the conventional alignment procedure (side view alignment). The results confirmed that flare measurement using the front view alignment is substantially equivalent to that using the side view alignment. Optical safety was evaluated in accordance with ANSI Z80.36-2021. The results demonstrated that the subject device meets the applicable requirements and is classified in Group 1 under ANSI Z80.36-2021, which indicates an ophthalmic instrument with no potential Page 5 {9} K261255 optical hazard. This classification is the same as that of the predicate device. The subject device was evaluated for the fundamental requirements of ophthalmic instruments in accordance with ISO 15004-1:2020. The results confirmed that the subject device meets the requirements of ISO 15004-1:2020. For biocompatibility, the chin rest and forehead rest of the subject device are made of the same materials including color additives as the 510(k) cleared device KOWA KT-800 (053444). Therefore, by reference to KOWA KT-800 (K053444), biocompatibility has been demonstrated. Electrical safety and electromagnetic compatibility (EMC) were evaluated in accordance with IEC 60601-1 and IEC 60601-1-2. The results confirmed that the subject device meets the applicable requirements and can be used safely in the intended use environment. A risk analysis was performed for immunity to electromagnetic sources described in Section IV.J of the FDA guidance, “Electromagnetic Compatibility (EMC) of Medical Devices”, and it was determined that the risks can be adequately mitigated through labeling. In addition, it was confirmed that EMC performance has been adequately evaluated in the test report based on IEC 60601-1-2. Software verification and validation (V&V) were conducted in accordance with IEC 62304 and the FDA guidance, “Content of Premarket Submissions for Device Software Functions” (issued June 14, 2023). The results confirmed that the software of the subject device operates as intended and has been appropriately designed, verified, and validated. For cybersecurity, an evaluation was conducted in accordance with IEC 81001-5-1 and the FDA guidance, “Cybersecurity in Medical Devices: Quality Management System Considerations and Content of Premarket Submissions” (issued Feb. 3, 2026). The results confirmed that, with appropriate risk controls implemented, there are no unacceptable residual risks. ## Conclusion The subject device shares the same fundamental technologies as the predicate device (K091039). The comparison between the subject device and the predicate device shows similarities with several differences. The non-clinical tests and evaluations described above were conducted to see if these differences raise any questions in safety and/or effectiveness of the subject device, and all test and evaluation results support that the subject device is as safe, as effective, and thus substantially equivalent to the predicate device. Page 6